docs(Overlay): fix simple typos (#6571)

www/src/pages/components/overlays.mdx

@@ -34,7 +34,7 @@ Things to know about the React-Bootstrap Overlay components.
 - The `<Tooltip>` and `<Popover>`
   components do not position themselves. Instead the `<Overlay>` (or `<OverlayTrigger>`)
   components, inject `ref` and `style` props.
-- Tooltip expects specific props injected by the `<Overlay>` component
+- Tooltip expects specific props injected by the `<Overlay>` component.
 - Tooltips for `disabled` elements must be triggered on a wrapper element.
 
 ## Overlay
@@ -47,7 +47,7 @@ adds support for transitions, and visibility toggling.
 
 Overlays consist of at least two elements, the "overlay", the element to
 be positioned, as well as a "target", the element the overlay is
-positioned in relation to. You can also also have an "arrow" element,
+positioned in relation to. You can also have an "arrow" element,
 like the tooltips and popovers, but that is optional. Be sure to
 check out the [Popper](https://popper.js.org/docs/v2)
 documentation for more details about the injected props.